Three-dimensional model expansion methods and systems

One or more non-transitory computer readable media comprising computer readable instructions which, when executed, configure a data processing system to perform:

• obtaining a to-be-expanded three-dimensional model;
• determining that the to-be-expanded three-dimensional model meets an expansion condition, wherein the expansion condition comprises that the model is orientable, the model does not comprise a non-manifold edge and a non-manifold vertex, and a geometric topology is a disc;
• determining a geometric area of each triangle mesh in the three-dimensional model;
• deleting one or more triangle meshes based on the determined geometric area of the one or more triangle meshes being zero;
• obtaining, based on remaining triangle meshes, an initial expansion result of the to-be-expanded three-dimensional model, wherein none of a plurality of triangular patches in the initial expansion result are flipped;
• determining a rigid transformation matrix of each triangular patch based on coordinate information of each triangular patch in the initial expansion result;
• determining first corrected coordinate information of each triangular patch based on the rigid transformation matrix of each triangular patch and a first energy function;
• determining, when there is a flipped triangular patch within the first corrected coordinate information, second corrected coordinate information of each triangular patch based on the rigid transformation matrix of each triangular patch and a second energy function, wherein the second energy function comprises the first energy function and an obstacle function component that can prevent the triangular patch from flipping;
• determining the second corrected coordinate information of each triangular patch as a target expansion result in a case that it is determined that a preset convergence condition is met;
• and
• generating, based on the target expansion result, a two-dimensional image representing a two-dimensional expansion of the to-be-expanded three-dimensional model.

A data processing device, comprising:

• one or more processors controlling operations of the data processing device;
• and
• memory storing computer readable instructions which, when executed, configure the data processing device to perform:
• obtaining a to-be-expanded three-dimensional model;
• determining that the to-be-expanded three-dimensional model meets an expansion condition, wherein the expansion condition comprises that the model is orientable, the model does not comprise a non-manifold edge and a non-manifold vertex, and a geometric topology is a disc;
• determining a geometric area of each triangle mesh in the three-dimensional model;
• deleting one or more triangle meshes based on the determined geometric area of the one or more triangle meshes being zero;
• obtaining, based on remaining triangle meshes, an initial expansion result of the to-be-expanded three-dimensional model, wherein none of a plurality of triangular patches in the initial expansion result are flipped;
• determining a rigid transformation matrix of each triangular patch based on coordinate information of each triangular patch in the initial expansion result;
• determining first corrected coordinate information of each triangular patch based on the rigid transformation matrix of each triangular patch and a first energy function;
• determining, when there is a flipped triangular patch within the first corrected coordinate information, second corrected coordinate information of each triangular patch based on the rigid transformation matrix of each triangular patch and a second energy function, wherein the second energy function comprises the first energy function and an obstacle function component that can prevent the triangular patch from flipping;
• determining the second corrected coordinate information of each triangular patch as a target expansion result in a case that it is determined that a preset convergence condition is met;
• and
• generating, based on the target expansion result, a two-dimensional image representing a two-dimensional expansion of the to-be-expanded three-dimensional model.